Centerless grinding machine



Dec. 3, 1929. r F. M. KERN 1,737,352

CENTERLESS GRINDING MACHINE` Original Filed April 1, 1926 3 ShSBtS-Sheet1 fred M.}(ern EM meg@ Dec. 3, 1929. F. M. KERN 1,737,852

CENTERLESS GRINDING MACHINE Original Filed April 1. 1926 3 Sheets-Sheet2 Jed M. Kern l tkouwq Dec. 3, 1929. F, M. KERN 117375852 CENTERLESSGRINDING 'UACHINE Original Filed April il, 1926 3 Sheets-Sheet 3gmc/nto@ red Mjfern and! was# Patented 3, 19294 UNITED STATES PATENTOFFICE FRED M. KERN, l' DETBOIT,`IIGHIGAN, ASBIGNOR, BY ASSIGNMENTS, T0Cuff CINNATI GRINDERS INCBPOBATED, 0l' CINCINNATI, OHIl A C OBPVORATlON'0F OHIO aannames Gnnmnm Application led April 1, 1929, Serial lo. 98,95@Renewed April 5, 1999.

tated grinding wheel and'a slowly rotated work regulating wheel.-

Heretofore, centerless grinding machines have been provided in which awork piece has beenpositioned for res ective grinding and rotationbetween a rapid y rotated grinding wheel and a slowly rotated workregulating wheel having its axis skewed at a Vslight angle to the axisof the grinding wheel (where both wheels are of the perip eral type)A soas to propel the work axially past and between' the wheels. Such amachine is not adapted for grindingj c lindrical work of special form,such as wor having a shoulder or enlargement thereon, since the latterprevents complete passage of the work axially past the wheels.

It is an object of the invention, therefore, to provide a centerlessgrinding machine for grinding such s cial shapes of cylindrical workeconomica y and accurately upon a commercial production basis.

It is a further object to provide a pipe or the like in a ceteilessgrinding machine for supplying grinding fluid upon the work piece duringthe grinding operation which is constructed and arran ed to convey thegrinding fluid in the most. a vantageous manner upon the Vworkregardless of any changes in the adjustments of the'machine required onaccount of wear of the rinding wheel or so that 4work of different sizesmay be ground.

The invention accordingly consists in the features of construction,combinations of elements, and arrangements of parts as will beexemplified in the structure to be hereinafter described and the scopeof the application of which will be indicated in the following claims.

machine as viewed from above in Fig. 1' the grindin wheel and certainother parts bein remove in order to show certain features o theconstruction more clearly;

- Fig. 3 is a detail view of the rack for carry ing the mounting for thework positioning4 member;

Fig. 4 is a detail view of the mounting for the positioning member;

' Fig. 5 is a side elevational view of a portion of the machine of Fig.1 and shows certain parts in section as seen along the line 5--5 of Fig.2;

Fig. 6 is an elevational view, partly in section of the eccentric shaftwhich supports the mointing for the work positioning member; an

Fig. 7 is a diagrammatic view of a machine in which the Wheels aredisposed in substantially the same horizontal plane and which embodiescertain features of the invention. A

' Similar reference characters refer to similar arts throughout theseveral views of the rawngs.

Referring now to the drawings I have shown in Figs. 1 to 6 a machineembodying a preferred form of the invention com rising a frame 10(Fig.'1) having a spind e11V mounted at an upper portion thereof forrotation. A grinding wheel 12 is mounted on the spindle end is rotatedrapidly and hence at a suitable inding speed from Vany suitable source opower by means of a belt 13 passing over a pulley 14 secured upon thespindle 11. A column 15 is mounted for vertical movement in a lowerfront but referably hollow cylindrical portion o frame and is preventedfrom turning therein by a key 17 en aging a groove 18 in the column. Aspin e 19 carrying a regulating wheel 20 is mounted for rotation insuitable bearings (not shown) within the bearin casing 21 upontliesupport 22 inte ral with or suitably securedl uponthe top o the column15, and -ma be rotated relatively slowly from any suitab e source ofpower, such as a motor 23 connected dii-eetl .with a shaft 24 carrying aworm 25 whic en es a worm wheel 26 secured uponI the spin le i9. y Thetwo wheels are rotated in the directions indicated the by the arrows inFig. 1 and it will be noted that the adjacent operative surfaces of thetwo'wheels are thus made to travel in opposite directions relative to apoint therebetween; the regulating wheel serves to control the rotationof work pieces of round section interposed between the two wheels, thegrinding wheel performing a grinding operation thereon during suchrotation.

An upwardly projecting bracket 27, formed preferably asan integral partof the column 15, is provided with vertically eX- tending slideways 28for receiving a slide 29 which may be adjusted vertically by turning ashaft 30 (see also Fig. 5) mounted inthe bracket 27 and carrying apinion 31 engaging a rack 32 on the sllde 29. A water pan 33 is securedto the eolumlr 15 by means 'of bolts 34 passing from the column into thesupport 22. The regulating wheel 2O and the bracket 27, as well as thewater pan 33, may be moved vertically by turning a screw shaft 35, whichis mounted (see Fig. 1) so as to prevent longitudinal movement in abearing (not shown) in the column 15 and is arranged to engage athreaded hole 36 in a vboss 37 secured to or integral with the frame l0.The screw shaft 35 may be turned by means of a hand wheel (not shown)secured upon a shaft 38 carrying a worm 39 which engages a'worm wheel4() mounted upon `the screw shaft 35.

In order that the work may be held in operative contact with thegrinding wheel and work regulating wheel while being ground to apredetermined si`ze by the former and rotated by the latter, I provide awork positioning or movable work holding member adapted to move the workinto the grinding throat between the wheels and preferably in adirection opposed to that in which the thrust of the rinding wheel isexerted thereon. Thus, re erring to Fig. 1, the operative surface of thegrinding wheel 12, adjacent the regulating wheel 20, will be seen tomove in a direction from the left to the right, and I achieve manyadvantages by causing the work positioning member to move the work pieceinto operative relation to the two wheels in a direction from the rightto the left as viewed in Fig. 1 and hence in a direction opposed to thatin which the thrust of the grindino wheel is exerted on the work. Asuitable and preferred form of mechanism for this purpose may include amounting 43 (see Fig. 4) supported fromthe slide 29 (Figs. 3 and 5) by ashaft 44 mounted for rotation in bearings 45 thereon. The shaft v44 isprovided with eccentric portions 46 (Fig. 6) integral with or otherwiseappropriately secured thereto, which are adapted to engage and rotatewithin bearings 47 (Fig. 4) in the mounting 43; A work moving member 48(Figs. 1, 2 and 5) is adjustably se` cured upon the projecting arms 49(Fig. 4)

on the mounting 43 \`by means of bolts 50 passing through the holes 5lin each arm. The mounting 43 is provided with an L shaped arm 52extending rearwardly therefrom and projecting thrpugh a slot (see Fig.5) in the bracket 27. The arm 52 has a'bearing plate 53 adapted toslidably engage a bearing plate 54 on the bracket 27. The extent of themovement of. the member 48 is limited by an adjust-able stop screw 55threaded into a lug 56 (Fig. 4) on the *arm 52, the stop screw beingarranged to engage the bracket 27. The mounting 43 is provided with aforwardly projecting guard 57 (Fig. 5) and an upwardly projecting guard58, the latter being adapted for movement beneath a cover 59 extendingdownwardly and out-V wardlyl from the slide 29. The bearing plate 53 isheld in contact with the bearing plate 54 by means of a plunger 60pressed upwardly by means vof a spring 61 surrounding a reduced .portionof the plunger in a hole 62 in a lug 63 extending from the bracket 27 Abearing plug G4, through which the 'reduced portion of the plunger 60passes, engagesa threaded portion of the hole 62 so as to press againstthe spring 61 and thus permit of ad'-,

justing the compression on the spring.

lVhen the work moving member 48 is withdrawn (in a direction to therightas viewed in Fig. l), the finished work may be discharged. Apreferred form of device for this purpose may include a reciprocatingplunger comprising a hollow casing 65 (Fig. 2)l adjustably mounted uponthe Water pan 33 by means of bolts G6 passing through a slot 67 in adownwardly depending bracket 68 integral with the casing 65. A hollowpiston 69 is slidably mounted within the casing G5 and normally is heldin the position shown in Fig. 2 by a spring 70 secured at one end to a'pin 71 in the piston 69 and at the other end to a pin 72 in the casing65. A pusher rod 73 is secured at the forward end of the piston 69 by a,clamp 74 and bolt 75. The other end of the piston 69 is provided withan ear 76 which project-s through a slot in the hollow casing 65 and isconnected, in the device illustrated, to one end of a rope 77 passingaround a pulley 78 mounted upon an arm 79 projecting from and integralwith the casing 65. The rope l77 is connected at its other end with amanually operated device which may control the operation of the plungeras will be more clearly described hereinafter.

The mounting 43 for the member 4'8 and the reciprocating plungery may beactuated by the same or different devicesJ which may be controlledmanually or by power through by a nut 90. The other end of the 4arm 88is secured to one end of the rope 77. A link 91 is pivotally mountedat'one end to the arm 88 and is provided near its other end with a slot92 adapted to engage an upwardly projecting pin 93 in the lever 85. Arod94 is,

pivotally secured at one end u on a stud 95 secured in a downwardl anforwardly' extending crank arm 96 Figs. 1f and 2).

The other end of the rod 94 is pivotally l mounted upon a stud 97secured in a bifurl cated end of a bolt 98 which is pivotally mounted onthe lever 85 and is secured thereon by means of a nut 99. The crank arm96 is rigidly secured to the shaft 44 by means of a key 101 (Fig. 6)engaging a slot -102v (Fig. l) in the crank arm.

A bracket 103 (Fig. 1) is adjustably secured to the bearing casing 21 bymeans of bolts 104 passing through a slot 105 in an arm 106 extending`downwardly from and integral with the bracket 103. A blade or workholding member 107 is adjustably mounted in the bracket 103 by means ofbolts 108 passing through elongated slots 109 in the member 107. Thebracket 103 is of hollow construction and is connected with a pipe 110so that the grinding fluid or coolant may run out over the member 107and directly upon the work lw held between the regulating wheel 20,grinding whel 12, member 48 and the member 107.

In operation, the grinding wheel 12 is rotated at a suitable grindingspeed (in the direction indicated by the arrow in Fig. 1) from anyappropriate source of powemby means of the belt 13, and the regulatlngWheel 204 is rotated slowly` (in the direction indicated by the arrow-inFig. 1) b means of the motor 23 and parts associate therewith.

`The regulating wheel 20 and the member 107 are moved vertically to anappropriate osition for the particular size of work to4 e ground, byturning a hand wheel secured upon the shaft 38. The blade`or member 107is then moved horizontally to a suitable position as determined by thesize of the finished work and the bolts 108 are tightened.

The positioning member 48 ma beadjusted vertically between theregulatlng wheel '2O and the grinding wheel 12 by turning the pinion 31engaging the rack 32 to raise or ower the slide 29 upon which the holder43 is mounted. The member 48 may be adjusted horizontally relative tomounting 43 by means of the bolts 50. The stop screw 55 is then adjustedso as to limit as desired the distance which the positioning member V48may travel toward a line connecting the centers of the grinding wheeland regulating the 'tact with the the wheel, that is, toward the left,as viwed in Figs. 1 and 5.

-With the movable work holding or work positioning-member 48 in itswithdrawn posiv tion, that is, in aposition to the right of that shownin Fig.`1, a work piece w, which may be assumed to be for example a workpiece having a shoulder or enlargement thereon such as a bolt, isinserted manually or otherwise between the grinding wheel 12, regulatingwheel 20, member 107 and the member 48, the enlarged or headed portionthereof overhan 'n the side face of the wheels and the en e ges of themembers 107 and 48. At this point it might further be noted' that withthe member 48 withdrawn toward the right, the inserted work piece restsupon the upper surface of the regulating wheel 20 and against the member48, being out of congrinding wheel 20 due to the fact that the adjacentoperative surfaces ozt1 the two wheels arek progressively more distantfrom each other throughout a substantial range extending substanti-allyfrom the work engaging face of the member 107 towardthe right as viewedin Fig. 1. Themovable work holding member 48 during this period acts toprevent the work piece w Afrom rolling ot of the regulatingwheel, theparts being so arranged, as will be clear from both Figs. 1 and 5, thatthe workpiece lw is positioned to the right of a vertical plane passingthrough the axis of the regulating wheel 20. Also during this period theslowly moving surface of the regulating wheel 2O keeps the work piece wrotating so that during the subsequent operations to be more clearlydescribed hereinafter the ultimate contact o f the work piece with thegrinding wheel finds the work piece in an already rotating condition.

By thereupon moving the lever 85 to the left and into substantially theposition shown in Fig. l or 'in a clockwise direction as viewed in Fig.2, the shaft 44 is rotated to move the eccentric portions 46 thereonwithin their bearings 47 and move the mounting 43 together with thepositioning member 48 forward (to th'e left as viewed in Figs. 1 and 5)towards grinding throat. In this manner the positioning member 48 movedwith the work lw to move the latter laterally into contact with thegrinding wheel and then feed or continue to move the work forward -intothe narrower portions of grindin throat and thus cause it to beprogressive y reduced in size. This member 48 maintains the. work inoperative contact with the wheels until it has been brought tothedesired predetermined size as limited by the setting of the stop screw55. Also the relatively fixed blade or work holdin member 107 ma besuitably set or adjuste to'such a position that the a work piece w willcome in contact with it as soon as the work piece hasbeen reduced to thedesired size, thus further preventing further movement of the workpiecetoward still narrower portions of the grinding throat. Y

wheels'where the latter are of the peripheral type and where one wheelis arranged above the two wheels.

the other, thereby insuring a movement of Ithe work piece in a directiontransversely of its axis and between progressively narrower portions ofthe grinding throat formed by It is also to be notedthat during theseactions the regulating wheel continues to control the rotation of thework piece w while the grinding wheel 12 performs a grinding operationthereon.

When theV grinding has been finished, the lever 85 is moved toward theright as viewed in Fig. 1 (or in counterclockwise direction as viewed inFig. 2) as quickly as is desired until the pin 9 3 is brought intoengagement with the rear end of the slot 92 (Fig. 2). This movement ofthe lever 85 acts through the linkages 94 96 to rotate the eccentricshaft 44 in reverse direction and thus to commence the movement of thepositioning member 48 .in a direction toward the right as viewed inFigs. 1 and 5, thus permitting the work piece fw, while still beingVrotated by the regulating vwheel 20, to roll toward the right and into awider portion of the grinding throat. -As the movement of the lever 85is continued toward the right, the arm 88 is turned about its pivot bolt89 to pull upon the rope 77 and thereby move the piston 69 against theaction of the spring 70 to force the pusher rod 73 axially between thewheels to discharge the ground work w. The lever 85 is then movedtowards the left (as viewed in Fig. 1) until the .pin 93 engages theforward end of the.

slot 92 thereby permitting the'spring 70 to return 'the pusher rod 73 tothe position shown in Fig. 2. Vith the lever 85 in this position thepositioning member '48 stands in its rearward position a sutiicientdistance from the grinding throat to permit replacement of the work. Anew work piece is then inserted between the wheels and in contact withthe positioning member 48, and the movement of the lever 85 is continuedtoward the left at a rate governed by the skill and experience of theoperator in the particular type ot' grinding operation being performeduntil the new work piece is brought to the desired predetermined size.

ln Fig. 7 of the drawings, I have indicated in a diagrammatic manner theapplication of the invention to a type of centerless grinding machine inwhich the centers of the grinding wheel and the work regulating wheelare positioned in substantially the same horizontal plane. Asillustrated, the grinding wheel 120 is mounted to be rotated rapidly inthe direction .indicated by the arrow by suitable mechanism, and thework regulating wheel 121 is similarly mounted for rotation slowl in thedirection indicated by the arrow.

work piece is positioned between the wheels 4means of a key 130 thereinadapted to engage a slot 131 in the crank arm. Movement of thepositioning member 122 upward may be limited by a stop screw 132adjustably mounted in a lug 133 in the frame 128 to engage the crank arm129. It will be now apparent in view of the foregoing to those skilledin the art that the work may be fed into the grind- `ingthroat betweenthe wheels so that it may be ground to a predetermined desired size bymoving the crank arm 129 to the right, and the positioning member 122may be withdrawn quickly to permit discharge of ground work by movingthe crank arm to the left.

Also, as will be seen in Fig. 7, I prefer in this vform of apparatus torelate the parts so that upon movement of the work holding member 122upwardly the work piece supported there- .bywill be moved toward theline connecting the centers of the two wheels and hence into contactwith the less and less distant portions of the two wheels; this relationof the parts is clearly indicated in Fig.'7. Also, it will be seen thatthe work piece carried by the member 122 is moved in a direction opposedto the downward thrust of the grinding wheel thereon andthat the extentof the grinding operation performed on the work while the latter isbeing rotated by the regulating wheel 121 may be predetermined byadjustment of the stop screw 132 which limits the movement of the crankarm 129.

It will therefore be seen that in accordance with certain features ofthe invention the work may be moved laterally into the narrowinggrinding throat between the wheels in opposition to the thrust of thegrinding wheel upon the work at a controllable rate, vthereby a machineadapted for economically and ediciently grinding successive work pieceshavin shoulders or enlargements thereon upon an e cient production basisto a predetermined size. It will be understood that I prefer to achievethe narrowing grinding throat for coaction with the work moving devicesabove described by utilizing peripherally opposed peripheral wheels butthat I may achieve many of the features of this invention'with othershapes of Wheels.

invention an apparatus in which the several objects hereinbefore notedas well as many advantages are successfully achieved and that theapparatus is well adapted to meet the varying conditions of hardpractical use.

As many possible embodiments may be made of the above invention and asmany changes might be made in the embodiment above set forth, it is tobe understood that all matter hereinbefore set forth or shown in theaccompanying drawings is to be interpreted as illustrative and not in alimiting sense.

Having thus described my invention, what claim as new and desire tosecure by Letters Patent is:

1. A centerless grinding machine comprising a rapidly rotated grindingwheel, a slowly rotated work regulating wheel, a positioning member formaintalning work of round section in operative contact with the wheels,and Y means for moving said member in a direction substantiallytransversely of the axis of the work piece and in opposition to thethrust of the grinding wheel to cause the work to be b ground to apredetermined size while being rotated by regulating wheel andthereafter withdraw it to permit removal and replace- .ing a rapidlyrotated grinding wheel, a s

ment of the finished work.

2. .A` centerless grindin machine comprising a rapidly'rotated grin ingwheel, a slowly rotated work regulating wheel, a work positioningmember, means for adjusting said member laterally and vertically toaccommodate different sizes of work, and a mechanism for moving saidmember to force the work into the grinding throat and cause it to beground to a predetermined size and thereafter permit discharge of thework.

3. A centerless grinding machine comprising a rapidly rotated grindingwheel, a slowly rotated work regulating wheel, a work positioning memberarranged to move work of round section into the grinding throat in adirection substantially transversely to the' axis of the work and'inopposition to the thrust of the grinding wheel so that the work may beground to a desired predetermined size and thereafter to withdraw,-. andmeans for discharging the ground w 'iik axially when said member iswithdrawnlz g.

4. A centerless grinding machine compris ow 1y rotated workregulating'wheel, a movable It will furthermore* be seen that there hasbeen provided in this work-positioning member, a mechanism for movinsaid member to force the work into the grinding throat in opposition tothe thrust of the grinding wheel until ground to a predetermined s izeand thereafter withdraw, a reciprocable plunger; Ifor discharging theground work when said member is withdrawn, and means for controlling themovement of said mechanism and said plunger and for' causing saidmechanism and said plunger 4to operate in proper sequence. y

5. In grinding apparatus, in combination, a grinding throat in whichwork'of round s ection is received for simultaneous "grindlng androtation, said grinding throat including a grinding wheel-rotatable atrelatively high speed, a regulating wheel rotatable at relatively lowspeed, vsaid wheels being adapted to present adjacent operative surfacestravcling in opposite directions, said wheels being opposed to oneanother and having their operative surfaces substantially approachingeach other so as to form a grinding throat of varying\width, and amovable member for holding work in operative relation to said twowheels, and means for moving said workhol'cling-member in a directionsubstantially transverselvof the axis of the work piece held hereby andwith the work piece interposed between it and the narrower portion ofsaid grinding throat so as to carry the, work toward the narrowerportion of said grinding throat, thereby teef-feet progressive reductionin diameter of thewvork, and means for limiting the movement of saidwork-holding memer. L

6. In grinding apparatus, in combination, a grinding wheel rotatable ata grinding speed, a' slowly rotated work-regulating wheel, `a memberfor'holdingw'ork in operative relation to said two wheels, means formoving said member. with a piece of work to be ground in a directionopposed to that in which the thrust of the grinding wheel is exerted,thereby to cause the l`,work to be ground tqa predetermined size',andfor thereaftenwithdrawing said memberto permit removal ofthegroundrwork, a-plunger movable in a direction to eiect the work piecefromthe grinding throat formedby said two wheels and mechanism foroperating said plunger .two wheels, and in a direction to move and 'holdthe work piece against the thrust of the grinding wheel while beingrotated by said regulating wheel. Y 8. In grinding aapparatus, incombmation, a grinding throatin'which work of round section is receivedfor simultaneous grlnding l and rotation, said grinding throatincluding' a. grinding wheel rotatable at relatively hlgh speed, aregulating wheel rotatable at relatively low speed, said wheels beingadapted to present adjacent operative surfaces traveling in oppositedirections and having their operativesurfaces substantially approachlngso as to form a grinding throat of varying width, means fon moving aWork plece substantially transversely of its axis mto said grinding-`throat, means for moving a'work piece out of said grinding throat, alever,

. means forming a direct connection between said lever and one of saidmeans for actuating the latter by said lever, and means forming a lostmotion connection between said lever and the other of said means foractuating the latter by said lever. Signed at Detroit, Michigan, this 27th day of March, 1926.

' lFRED M. KERN.

DISCLAIMER 1,737,852.Ifred M. Kern, Detroit, Mich. CENTERLESS GRINDlNcMAUHINE. Patent dated December 3, 1929. Disclaimer filed April 3, 1931,by the `assignee,.Uz'rz'fnratz' Grinders I aaorporated.v

Hereby enters this disclaimer tothe subject matter of claims l, 5, and 7in the said specification, which claims read as follows 1. A centerlessgrinding machine comprising a rapidly rotated grinding wheel, a slowlyrotated work regulating wheel, a positioning member for-maintaining workof round section inoperative contact with the wheels, and means formoving said member in a direction substantially transversely of the aXisof the owork piece and in opposition to the thrust of the grinding wheelto cause the work to be ground to a predetermined size while beingrotated by said regulating Wheel and thereafter withdraw it to permit.removal and replacement ofthe finished work.

5.`In grindingv apparatus, in combination, al grinding throat in whichwork of round section is received for simultaneousgrinding andirotation, said grinding `throat including a grinding Wheel rotatable atrelatively high speed, a regulating wheel rotatable at relatively lowspeed,.said Wheelsbeing adapted to present adjacent operative surfacestraveling 1n opposite directions, said wheels beingopposed to oneanother and having their operative surfaces" substantially approachingeac-h other so as to `form a grinding throat-of varying width, and amovable member for holding work in operative relation tosaid two wheels,and means for moving said work-holding member .in a directionsubstantially transversely of the axis of the work piece held therebyand with the work piece interposed between it and the narrower portionof said grinding throat so` as to carry the worktoward the narrowerportion/of Ysaid. grinding-throat, thereby to effect progressivereduction in diameter ofthe work, and means for limiting the movement ofsaid work-holding member.

7. 'In grinding apparatus, in combination, a rapidlyl rotated grindingWheel, a slowly rotated work-regulating Wheel, fi-movable member forholding work of roundsection between said wheels, and means 'for movingsaid member with a work piece thereon in an direction substantiallytransversely of the axis of the work, thereby to carry 'said work pieceinto the grinding throat formed by said two wheels, and ina direction tomove and hold the work piece against the thrust of the grinding' wheelwhile being rotated by said regulating'wheel.

[Oficial Gazette April 21, 1.931

